DESCRIPTION: (Principal Investigator's Abstract) The incidence of infections caused by Yeasts has increased in recent years due to increases in the number of immuno-compromised patients (e.g., AIDS, Cancer). Because Yeasts grow slowly, it is difficult but important to develop rapid methods for their identification. Biolog holds two patents on a new redox method which identifies an organism based on patterns of carbon source utilization. The method employs a tetrazolium dye to colorimetrically indicate carbon source oxidations. Principal advantages of the method are: (1) speed--for most microorganisms tests can be completed in 4 to 24 hours, (2) simplicity--this is an easy to inoculate and read single color chemistry, and (3) accuracy-- drawing from hundreds of potential carbon sources should enable us to develop a test panel tht (sic) is far more accurate than anything presently available. In Phase I, 19 species and 34 strains were tested against 380 carbon sources. A feasible 62-test prototype kit was demonstrated that could distinguish all strains by an average of 18 tests. In Phase II, the survey will be greatly expanded to include all 70 species of clinically encountered yeast. 2000 strains and 380 carbon sources will be examined. From the results of this study a final prototype kit will be produced. The prototype will be evaluated in a collaborative clinical study.